Research on the method of rapid and accurate extraction of boundary points by hierarchy

In order to improve the extraction efficiency of the boundary point extraction method based on the maximum Angle of adjacent points, a hierarchical fast and accurate boundary point extraction method was proposed. R in the neighborhood at any sampling point set was firstly retrieved, followed by the crude extraction of boundary point according to the distance from the center of gravity point coordinates to the sampling point in the R neighborhood point set. The crude extract of boundary points and their neighborhood points were then projected to the tangent plane, and the maximum angle between adjacent vectors was calculated through the adjacent points and sampling points in the direction of the vector, the final accurate boundary point was then extracted based on the maximum angle. Through theoretical analysis and point cloud data experiment, the feasibility of the algorithm was verified. The results show that this algorithm can respectively shorten the running time by 22.11% and the accuracy by 5.23% compared with the traditional method, and can respectively shorten the running time by 10.99% and improve the accuracy by 7.17% compared with other hierarchical extraction methods. This study provides a reference for boundary extraction in point cloud 3-D reconstruction.